Charge transport materials for luminescent applications

ABSTRACT

There is provided a charge transport compound having the formula T-LG-T, where T is a charge transport moiety having the formula —Ar 1 -An-Ar 2  and LG is a linking group. In the compound, An is a divalent anthracene moiety; Ar1 is a single bond or an aromatic group which can be naphthyl, binaphthyl, naphthylphenylene, naphthylbiphenylene, or naphthylbinaphthylene; Ar2 is an aromatic group which can be naphthyl, binaphthyl, naphthylphenylene, naphthylbiphenylene, or naphthylbinaphthylene; and LG can be biphenylene, binaphthylene, or Formula I 
                         
In Formula I, Q1 and Q2 are the same or different can be alkyl and aryl, or Q1 and Q2 taken together can be alkylene; and Ar3 and Ar4 are the same or different and can be phenylene or naphthylene.

RELATED APPLICATION DATA

This application claims priority under 35 U.S.C. §119(e) from U.S.Provisional Application No. 60/941,392 filed on Jun. 1, 2007, which isincorporated by reference herein in its entirety.

BACKGROUND INFORMATION

1. Field of the Disclosure

This disclosure relates in general to materials that can be used ashosts for light-emitting materials in luminescent applications. Thedisclosure further relates to electronic devices having at least oneactive layer comprising such a host material.

2. Description of the Related Art

In organic photoactive electronic devices, such as organic lightemitting diodes (“OLED”), that make up OLED displays, the organic activelayer is sandwiched between two electrical contact layers in an OLEDdisplay. In an OLED, the organic photoactive layer emits light throughthe light-transmitting electrical contact layer upon application of avoltage across the electrical contact layers.

It is well known to use organic electroluminescent compounds as theactive component in light-emitting diodes. Simple organic molecules,conjugated polymers, and organometallic complexes have been used.Devices that use photoactive materials frequently include one or morecharge transport layers, which are positioned between a photoactive(e.g., light-emitting) layer and a contact layer (hole-injecting contactlayer). A device can contain two or more contact layers. A holetransport layer can be positioned between the photoactive layer and thehole-injecting contact layer. The hole-injecting contact layer may alsobe called the anode. An electron transport layer can be positionedbetween the photoactive layer and the electron-injecting contact layer.The electron-injecting contact layer may also be called the cathode.Charge transport materials can also be used as hosts in combination withthe photoactive materials.

There is a continuing need for charge transport materials for use inelectronic devices.

SUMMARY OF THE DISCLOSURE

There is provided a compound having the formula T-LG-T, where T is acharge transport moiety having the formula —Ar¹-An-Ar² and LG is alinking group,

wherein:

-   -   An is a divalent anthracene moiety;    -   Ar1 is a single bond or an aromatic group selected from the        group consisting of naphthyl, binaphthyl, naphthylphenylene,        naphthylbiphenylene, and naphthylbinaphthylene;    -   Ar2 is an aromatic group selected from the group consisting of        naphthyl, binaphthyl, naphthylphenylene, naphthylbiphenylene,        and naphthylbinaphthylene; and    -   LG is selected from the group consisting of biphenylene,        binaphthylene, and Formula I

wherein

-   -   Q1 and Q2 are the same or different and are selected from the        group consisting of alkyl and aryl, or Q1 and Q2 taken together        are alkylene, and    -   Ar3 and Ar4 are the same or different and are selected from the        group consisting of phenylene and naphthylene.

There is also provided an electronic device comprising at least onelayer comprising the above compound.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated in the accompanying figures to improveunderstanding of concepts as presented herein.

FIG. 1 includes an illustration of one example of an organic electronicdevice.

Skilled artisans appreciate that objects in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the objects in the figures may beexaggerated relative to other objects to help to improve understandingof embodiments.

DETAILED DESCRIPTION

Many aspects and embodiments are described herein and are merelyexemplary and not limiting. After reading this specification, skilledartisans will appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms followed by the Charge Transport Materials, theElectronic Device, and finally Examples.

1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms aredefined or clarified.

The phrase “adjacent to,” when used to refer to layers in a device, doesnot necessarily mean that one layer is immediately next to anotherlayer. On the other hand, the phrase “adjacent R groups,” is used torefer to R groups that are next to each other in a chemical formula(i.e., R groups that are on atoms joined by a bond).

The term “alkyl” is intended to mean a group derived from an aliphatichydrocarbon having one point of attachment, and includes a linear, abranched, or a cyclic group. The term is intended to includeheteroalkyls. The term “alkylene” is intended to mean a group derivedfrom an aliphatic hydrocarbon and having two or more points ofattachment. In some embodiments, an alkyl group has from 1-20 carbonatoms.

The term “aryl” is intended to mean a group derived from an aromatichydrocarbon having one point of attachment. The term is intended toinclude heteroaryls. The term “arylene” is intended to mean a groupderived from an aromatic hydrocarbon having two points of attachment. Insome embodiments, an aryl group has from 3-60 carbon atoms.

The term “binaphthyl” is intended to mean a group having two naphthaleneunits joined by a single bond. In some embodiments, the binaphthyl groupis 1,1-binaphthyl, which is attached at the 3-, 4-, or 5-position; insome embodiments, 1,2-binaphthyl, which is attached at the 3-, 4-, or5-position on the 1-naphthyl moiety, or the 4- or 5-position on the2-naphthyl moiety; and in some embodiments, 2,2-binaphthyl, which isattached at the 4- or 5-position.

The term “blue” refers to radiation that has an emission maximum at awavelength in a range of approximately 400-500 nm.

The term “charge transport,” when referring to a layer, material,member, or structure is intended to mean such layer, material, member,or structure facilitates migration of such charge through the thicknessof such layer, material, member, or structure with relative efficiencyand small loss of charge. Hole transport materials facilitate positivecharge; electron transport material facilitate negative charge. Althoughlight-emitting materials may also have some charge transport properties,the term “charge transport layer, material, member, or structure” is notintended to include a layer, material, member, or structure whoseprimary function is light emission.

The prefix “fluoro” indicates that one or more hydrogen atoms have beenreplaced with a fluorine atom.

The prefix “hetero” indicates that one or more carbon atoms have beenreplaced with a different atom. In some embodiments, the different atomis N, O, or S.

The term “layer” is used interchangeably with the term “film” and refersto a coating covering a desired area. The term is not limited by size.The area can be as large as an entire device or as small as a specificfunctional area such as the actual visual display, or as small as asingle sub-pixel. Layers and films can be formed by any conventionaldeposition technique, including vapor deposition, liquid deposition(continuous and discontinuous techniques), and thermal transfer.Continuous deposition techniques, include but are not limited to, spincoating, gravure coating, curtain coating, dip coating, slot-diecoating, spray coating, and continuous nozzle coating. Discontinuousdeposition techniques include, but are not limited to, ink jet printing,gravure printing, and screen printing.

The term “organic electronic device,” or sometimes just “electronicdevice,” is intended to mean a device including one or more organicsemiconductor layers or materials.

Unless otherwise indicated, all groups can be substituted orunsubstituted. An optionally substituted group, such as, but not limitedto, alkyl or aryl, may be substituted with one or more substituentswhich may be the same or different. Suitable substituents include alkyl,aryl, nitro, cyano, —N(R⁷)(R⁸), halo, hydroxy, carboxy, alkenyl,alkynyl, cycloalkyl, heteroaryl, alkoxy, aryloxy, heteroaryloxy,alkoxycarbonyl, perfluoroalkyl, perfluoroalkoxy, arylalkyl, thioalkoxy,—S(O)₂—N(R′)(R″), —C(═O)—N(R′)(R″), (R′)(R″)N-alkyl,(R′)(R″)N-alkoxyalkyl, (R′)(R″)N-alkylaryloxyalkyl, —S(O)_(s)-aryl(where s=0-2) or —S(O)_(s)-heteroaryl (where s=0-2). Each R′ and R″ isindependently an optionally substituted alkyl, cycloalkyl, or arylgroup. R′ and R″, together with the nitrogen atom to which they arebound, can form a ring system in certain embodiments.

The term “photoactive” is intended to mean to any material that exhibitselectroluminescence or photosensitivity.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of “a” or “an” are employed to describe elements andcomponents described herein. This is done merely for convenience and togive a general sense of the scope of the invention. This descriptionshould be read to include one or at least one and the singular alsoincludes the plural unless it is obvious that it is meant otherwise.

Group numbers corresponding to columns within the Periodic Table of theelements use the “New Notation” convention as seen in the CRC Handbookof Chemistry and Physics, 81^(st) Edition (2000-2001).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of embodiments of the present invention, suitablemethods and materials are described below. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety, unless a particular passageis cited. In case of conflict, the present specification, includingdefinitions, will control. In addition, the materials, methods, andexamples are illustrative only and not intended to be limiting.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductive memberarts.

2. Charge Transport Materials

The new compounds described herein are particularly useful as hostmaterials for photoactive materials. The compounds have the formulaT-LG-T, where T is a charge transport moiety and LG is a linking group.

The charge transport moiety has the formula —Ar¹-An-Ar²

wherein:

-   -   An is a divalent anthracene moiety;    -   Ar1 is a single bond or an aromatic group selected from the        group consisting of naphthyl, binaphthyl, naphthylphenylene,        naphthylbiphenylene, and naphthylbinaphthylene; and    -   Ar2 is an aromatic group selected from the group consisting of        naphthyl, binaphthyl, naphthylphenylene, naphthylbiphenylene,        and naphthylbinaphthylene.

In some embodiments, An is an anthracene attached at the 9- and10-positions. In some embodiments, the anthracene moiety has at leastone substituent. In some embodiments, the substituent is selected fromthe group consisting of C1-12 alkyl and C1-12 alkoxy. In someembodiments, the anthracene is substituted at the 2- and 6-position.

In some embodiments, the charge transport moiety T is selected fromgroups A-G below.

In the above groups, possible points of attachment to LG are shownas - - - *. The above groups may also be substituted.

-   -   LG is a linking group and is selected from the group consisting        of biphenylene, binaphthylene, and Formula I

wherein

-   -   Q1 and Q2 are the same or different and are selected from the        group consisting of alkyl and aryl, or Q1 and Q2 taken together        are alkylene, and    -   Ar3 and Ar4 are the same or different and are selected from the        group consisting of phenylene and napthylene.

In some embodiments, LG has Formula II:

In some embodiments, Q1 and Q2 are independently selected from the groupconsisting of methyl, trifluoromethyl, and phenyl. In some embodiments,Q1=Q2.

In some embodiments, Q1 and Q2 taken together form an alkylene groupselected from the group consisting of cyclohexylene and 3,4-hexylene.

In some embodiments, LG is 1,4-phenylene.

In some embodiments, LG is a binaphthylene group. In some embodiments,4,4′-(1,1′-binaphthylene). In some embodiments, the binapthylene grouphas at least one substituent selected from the group consisting of C1-12alkyl and C1-12 alkoxy.

In some embodiments, LG has Formula III:

where R1 and R2 are the same or different and are C1-1 2 alkyl groups.In some embodiments, R1 and R2 are C6-10 groups.

In some embodiments, the new charge transport compound is Compound H1through H5 below.

The new charge transport compounds can be prepared by known coupling andsubstitution reactions. An exemplary preparation is given in theExamples.

The new compounds described herein can be formed into films using liquiddeposition techniques.

3. Electronic Device

The present invention also relates to an electronic device comprising atleast one photoactive layer positioned between two electrical contactlayers, wherein the at least one layer of the device includes the newcharge transport compound described herein.

Organic electronic devices that may benefit from having one or morelayers comprising the new charge transport materials described hereininclude, but are not limited to, (1) devices that convert electricalenergy into radiation (e.g., a light-emitting diode, light emittingdiode display, or diode laser), (2) devices that detect signals throughelectronics processes (e.g., photodetectors, photoconductive cells,photoresistors, photoswitches, phototransistors, phototubes, IRdetectors), (3) devices that convert radiation into electrical energy,(e.g., a photovoltaic device or solar cell), and (4) devices thatinclude one or more electronic components that include one or moreorganic semi-conductor layers (e.g., a transistor or diode).

One illustration of an organic electronic device structure is shown inFIG. 1. The device 100 has a first electrical contact layer, an anodelayer 110 and a second electrical contact layer, a cathode layer 160,and a photoactive layer 140 between them. Adjacent to the anode is abuffer layer 120. Adjacent to the buffer layer is a hole transport layer130, comprising hole transport material. Adjacent to the cathode may bean electron transport layer 150, comprising an electron transportmaterial. As an option, devices may use one or more additional holeinjection or hole transport layers (not shown) next to the anode 110and/or one or more additional electron injection or electron transportlayers (not shown) next to the cathode 160.

Layers 120 through 150 are individually and collectively referred to asthe active layers.

In one embodiment, the different layers have the following range ofthicknesses: anode 110, 500-5000 Å, in one embodiment 1000-2000 Å;buffer layer 120, 50-2000 Å, in one embodiment 200-1000 Å; holetransport layer 130, 50-2000 Å, in one embodiment 200-1000 Å;photoactive layer 140, 10-2000 Å, in one embodiment 100-1000 Å; layer150, 50-2000 Å, in one embodiment 100-1000 Å; cathode 160, 200-10000 Å,in one embodiment 300-5000 Å. The location of the electron-holerecombination zone in the device, and thus the emission spectrum of thedevice, can be affected by the relative thickness of each layer. Thedesired ratio of layer thicknesses will depend on the exact nature ofthe materials used.

Depending upon the application of the device 100, the photoactive layer140 can be a light-emitting layer that is activated by an appliedvoltage (such as in a light-emitting diode or light-emittingelectrochemical cell), or a layer of material that responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). Examples of photodetectors includephotoconductive cells, photoresistors, photoswitches, phototransistors,and phototubes, and photovoltaic cells, as these terms are described inMarkus, John, Electronics and Nucleonics Dictionary, 470 and 476(McGraw-Hill, Inc. 1966).

The charge transport compounds described herein can be present in thephotoactive layer or in a charge transport layer.

a. Photoactive Layer

The charge transport compounds described herein are useful as hosts forthe photoactive materials in layer 140.

The photoactive material can be any electroluminescent (“EL”) materialhaving the desired color. Electroluminescent materials include smallmolecule organic fluorescent compounds, fluorescent and phosphorescentmetal complexes, conjugated polymers, and mixtures thereof. Examples offluorescent compounds include, but are not limited to, pyrene, perylene,rubrene, coumarin, derivatives thereof, and mixtures thereof. Examplesof metal complexes include, but are not limited to, metal chelatedoxinoid compounds, such as tris(8-hydroxyquinolato)aluminum (Alq3);cyclometalated iridium and platinum electroluminescent compounds, suchas complexes of iridium with phenylpyridine, phenylquinoline, orphenylpyrimidine ligands as disclosed in Petrov et al., U.S. Pat. No.6,670,645 and Published PCT Applications WO 03/063555 and WO2004/016710, and organometallic complexes described in, for example,Published PCT Applications WO 03/008424, WO 03/091688, and WO 03/040257,and mixtures thereof. Electroluminescent emissive layers comprising acharge carrying host material and a metal complex have been described byThompson et al., in U.S. Pat. No. 6,303,238, and by Burrows and Thompsonin published PCT applications WO 00/70655 and WO 01/41512. Examples ofconjugated polymers include, but are not limited topoly(phenylenevinylenes), polyfluorenes, poly(spirobifluorenes),polythiophenes, poly(p-phenylenes), copolymers thereof, and mixturesthereof.

In some embodiments, the EL material is a cyclometalated complex ofiridium. In some embodiments, the complex has two ligands selected fromphenylpyridines, phenylquinolines, and phenylisoquinolines, and a thirdligand with is a β-dienolate. The ligands may be unsubstituted orsubstituted with F, D, alkyl, CN, or aryl groups.

In some embodiments, the EL material is selected from the groupconsisting of a non-polymeric spirobifluorene compound and afluoranthene compound.

In some embodiments, the EL material is a compound having aryl aminegroups. In one embodiment, the EL material is selected from the formulaebelow:

where:

A is the same or different at each occurrence and is an aromatic grouphaving from 3-60 carbon atoms;

Q is a single bond or an aromatic group having from 3-60 carbon atoms;

n and m are independently an integer from 1-6.

In one embodiment of the above formula, at least one of A and Q in eachformula has at least three condensed rings. In one embodiment, m and nare equal to 1. In one embodiment, Q is a styryl or styrylphenyl group.

In some embodiments, Q is an aromatic group having at least twocondensed rings. In some embodiments, Q is selected from the groupconsisting of naphthalene, anthracene, chrysene, pyrene, tetracene,xanthene, perylene, coumarin, rhodamine, quinacridone, and rubrene. Insome embodiments, A is selected from the group consisting of phenyl,tolyl, naphthyl, and anthracenyl groups.

In one embodiment, the EL material has the formula below:

where:

Y is the same or different at each occurrence and is an aromatic grouphaving 3-60 carbon atoms;

Q′ is an aromatic group, a divalent triphenylamine residue group, or asingle bond.

In some embodiments, the EL material is an aryl acene. In someembodiments, the EL material is a non-symmetrical aryl acene. In someembodiments, the EL material is a chrysene derivative. The term“chrysene” is intended to mean 1,2-benzophenanthrene. In someembodiments, the EL material is a chrysene having aryl substituents. Insome embodiments, the EL material is a chrysene having arylaminosubstituents. In some embodiments, the EL material is a chrysene havingtwo different arylamino substituents.

In some embodiments, the EL material has blue or green emission.

In some embodiments, the ratio of host material to EL material is in therange of 5:1 to 20:1; in some embodiments, 10:1 to 15:1.

The new charge transport compounds described herein are particularlyuseful as hosts for fluorescent organic compounds, including aromaticand arylamino-aromatic compounds.

b. Other Device Layers

The other layers in the device can be made of any materials that areknown to be useful in such layers.

The anode 110, is an electrode that is particularly efficient forinjecting positive charge carriers. It can be made of, for example,materials containing a metal, mixed metal, alloy, metal oxide ormixed-metal oxide, or it can be a conducting polymer, or mixturesthereof. Suitable metals include the Group 11 metals, the metals inGroups 4-6, and the Group 8-10 transition metals. If the anode is to belight-transmitting, mixed-metal oxides of Groups 12, 13 and 14 metals,such as indium-tin-oxide, are generally used. The anode 110 can alsocomprise an organic material such as polyaniline as described in“Flexible light-emitting diodes made from soluble conducting polymer,”Nature vol. 357, pp 477-479 (11 Jun. 1992). At least one of the anodeand cathode is desirably at least partially transparent to allow thegenerated light to be observed.

The buffer layer 120 comprises buffer material and may have one or morefunctions in an organic electronic device, including but not limited to,planarization of the underlying layer, charge transport and/or chargeinjection properties, scavenging of impurities such as oxygen or metalions, and other aspects to facilitate or to improve the performance ofthe organic electronic device. Buffer materials may be polymers,oligomers, or small molecules. They may be vapour deposited or depositedfrom liquids which may be in the form of solutions, dispersions,suspensions, emulsions, colloidal mixtures, or other compositions.

The buffer layer can be formed with polymeric materials, such aspolyaniline (PANI) or polyethylenedioxythiophene (PEDOT), which areoften doped with protonic acids. The protonic acids can be, for example,poly(styrenesulfonic acid), poly(2-acrylamido-2-methyl-1-propanesulfonicacid), and the like.

The buffer layer can comprise charge transfer compounds, and the like,such as copper phthalocyanine and thetetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ).

In some embodiments, the buffer layer comprises at least oneelectrically conductive polymer and at least one fluorinated acidpolymer. Such materials have been described in, for example, publishedU.S. patent applications 2004-0102577, 2004-0127637, and 2005/205860

Examples of hole transport materials for layer 130 have been summarizedfor example, in Kirk-Othmer Encyclopedia of Chemical Technology, FourthEdition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole transportingmolecules and polymers can be used. Commonly used hole transportingmolecules are:N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]-4,4′-diamine(TPD), 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (TAPC),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD), tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA),a-phenyl-4-N,N-diphenylaminostyrene (TPS), p-(diethylamino)benzaldehydediphenylhydrazone (DEH), triphenylamine (TPA),bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB),N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB), andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers are polyvinylcarbazole, (phenylmethyl)-polysilane,and polyaniline. It is also possible to obtain hole transportingpolymers by doping hole transporting molecules such as those mentionedabove into polymers such as polystyrene and polycarbonate. In somecases, a polymer of triarylamine is used, particularly a copolymer oftriarylamine and fluorene. In some cases the polymer or copolymer iscrosslinkable.

Examples of additional electron transport materials which can be used inlayer 150 include metal chelated oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq₃);bis(2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(III)(BAIQ); and azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD) and3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthroline derivativessuch as 9,10-diphenylphenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and mixturesthereof. Layer 150 can function both to facilitate electron transport,and also serve as a buffer layer or confinement layer to preventquenching of the exciton at layer interfaces. Preferably, this layerpromotes electron mobility and reduces exciton quenching.

The cathode 160, is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used. Li-containing organometalliccompounds, LiF, and Li₂O can also be deposited between the organic layerand the cathode layer to lower the operating voltage.

It is known to have other layers in organic electronic devices. Forexample, there can be a layer (not shown) between the anode 110 andbuffer layer 120 to control the amount of positive charge injectedand/or to provide band-gap matching of the layers, or to function as aprotective layer. Layers that are known in the art can be used, such ascopper phthalocyanine, silicon oxy-nitride, fluorocarbons, silanes, oran ultra-thin layer of a metal, such as Pt. Alternatively, some or allof anode layer 110, active layers 120, 130, 140, and 150, or cathodelayer 160, can be surface-treated to increase charge carrier transportefficiency. The choice of materials for each of the component layers ispreferably determined by balancing the positive and negative charges inthe emitter layer to provide a device with high electroluminescenceefficiency.

It is understood that each functional layer can be made up of more thanone layer.

The device can be prepared by a variety of techniques, includingsequential vapor deposition of the individual layers on a suitablesubstrate. Substrates such as glass, plastics, and metals can be used.Conventional vapor deposition techniques can be used, such as thermalevaporation, chemical vapor deposition, and the like. Alternatively, theorganic layers can be applied from solutions or dispersions in suitablesolvents, using conventional coating or printing techniques, includingbut not limited to spin-coating, dip-coating, roll-to-roll techniques,ink-jet printing, screen-printing, gravure printing and the like. Thenew charge transport compounds described herein are particularly suitedto liquid deposition processes for forming films.

Devices frequently have additional hole transport and electron transportlayers.

It is understood that the efficiency of devices made with the chrysenecompounds described herein, can be further improved by optimizing theother layers in the device. For example, more efficient cathodes such asCa, Ba or LiF can be used. Shaped substrates and novel hole transportmaterials that result in a reduction in operating voltage or increasequantum efficiency are also applicable. Additional layers can also beadded to tailor the energy levels of the various layers and facilitateelectroluminescence.

EXAMPLES Example 1

This example illustrates the preparation of Compound H5,10,10′-(6,6′-(4,4′-(perfluoropropane-2,2-diyl)bis(4,1-phenylene))bis(naphthalene-6,2-diyl))bis(9-(4-methylnaphthalen-1-yl)anthracene).

Relative Amount Amount MW Equiva- Compound (g) (mmol) (g/mol) lents6,6′-(4,4′-(perfluoropropane- 1.70 2.00 852.66 1.002,2-diyl)bis(4,1-phenylene))bis (naphthalene-6,2-diyl)bis(trifluoromethanesulfonate) 4,4,5,5-tetramethyl-2-(10-(4- 1.81 4.20430.35 2.10 methylnaphthalen-1- yl)anthracen-9-yl)-1,3,2- dioxaborolanePd(dppf)₂Cl₂ 65 mg 0.08 816.63 0.04 Potassium phosphate 3.68 16.00230.28 8.00 K₃PO₄•H₂O Sodium carbonate 8.00 mL 16.00 105.99 8.00 Na₂CO₃(2M) THF 60 (mL) 10,10′-(6,6′-(4,4′- 2.32 3.00 1161.28(perfluoropropane-2,2- (Theo- diyl)bis(4,1- retical)phenylene))bis(naphthalene- 6,2-diyl))bis(9-(4- methylnaphthalen-1-yl)anthracene)

All reagents, except the Pd catalyst, and solvents were added to a 250mL two-necked round bottom flask equipped with a magnetic stirrer and areflux condenser, which was attached to a nitrogen line. With stirring,the system was purged with nitrogen (with N₂ flowing in from the top ofcondenser and bubbling through the solution) for 20 min. The Pd catalystwas added and the system was purged for another 15 min. The reactionmixture was stirred and refluxed under nitrogen overnight. During thetime some solid was observed. At the end of the reaction, water (50 mL)was added and the mixture was stirred at ambient temperature for 2 hour.The crude product was collected by filtration, washed with water thenwith methanol (400 mL) dried in a vacuum oven overnight. TLC analysis ofthe solid material indicated that all starting triflate had beenconsumed and the product appeared as the major spot with a bright bluecolor under UV light irradiation. The Rf value of the product was foundsimilar to that of starting triflate but it was seen non-fluorescent.The crude product was then dissolved in toluene (150 mL) with gentleheating under nitrogen and stirred with active carbon (20 g) at ambienttemperature for 2 hr. After which, the solution was filtered through abed of Florosil* and the solvent was removed by rotary evaporation. Theproduct was further purified by crystallization from DCM/Hexane to givethe product as a white powder, yield, 1.75 g (75%) with a purity >99.9%by HPLC analysis. NMR spectra are consistent with the structuresexpected.

Example 2

This example illustrates the preparation of Compound H2,10,10′-(4,4′-(2,2′-dioctyl-1,1′-binaphthyl-4,4′-diyl)bis(4,1-phenylene))bis(9-(naphthalen-2-yl)anthracene).

Relative Amount Amount MW Equiva- Compound (g) (mmol) (g/mol) lents4-(10-(naphthalen-2- 2.71 5.125 528.54 2.05 yl)anthracen-9-yl)phenyltrifluoromethanesulfonate 2,2′-(2,2′-dioctyl-1,1′- 1.83 2.50 730.67 1.00binaphthyl-4,4′- diyl)bis(4,4,5,5-tetramethyl- 1,3,2-dioxaborolane)Pd(dppf)₂Cl₂ 82 mg 0.10 816.63 0.04 Potassium phosphate 4.60 20.00230.28 8.00 K₃PO₄•H₂O Sodium carbonate 10.0 mL 20.00 105.99 8.00 Na₂CO₃(2M) THF 80.0 (mL) 10,10′-(4,4′-(2,2′-dioctyl-1,1′ 3.09 2.50 1235.68binaphthyl-4,4′-diyl)bis(4,1- (Theo- phenylene))bis(9- retical)(naphthalen-2-yl)anthracene)

All reagents, except the Pd catalyst, and solvents were added to a 250mL three-necked round bottom flask equipped with a magnetic stirrer anda reflux condenser, which was attached to a nitrogen line. Withstirring, the system was purged with nitrogen (with N₂ flowing in fromthe top of condenser and bubbling through the solution) for 20 min. ThePd catalyst was added and the system was purged for another 15 min. Thereaction mixture was stirred and refluxed (in an oil bath at 80° C.)under nitrogen overnight. HPLC analysis indicated that only 27% of theproduct had been formed. More triflate (0.40 g) and Pd catalyst (82 mg)were added and the reaction was continued for another 2 days. HPLCanalysis on the organic layer indicated that almost all binaphthyldiborate had been consumed and the product appeared as a major spot withstrong blue fluorescence under UV light irradiation. The organic layerwas diluted with toluene (100 mL) and separated. The aqueous layer wasextracted with toluene (2×25 mL). The organic fractions were combined,washed with diluted HCl (5%, 1×60 mL) water (2×60 mL) and saturatedbrine (60 mL), and dried with MgSO₄. The volume of the solution wasreduced to about 8 mL on a rotavap and then added dropwise to methanol(200 mL) with stirring. After stirring for 20 min the precipitate wascollected by filtration and dried in a vacuum oven at RT overnight togive 3.05 g of light brown powder. The crude product was dissolved in aminimum volume of toluene (4-5 mL) and precipitated two more times frommethanol with the purity of the product improved to ˜90% by HPLC. Thecrude product was then purified by chromatography on a Florosil* columneluted with DCM/hexane (1/5, 1/4). The product containing fractions werecombined and the solvent was removed by rotary evaporation to give awhite powder with a purity of 95-96%. The product was further cleaned byprecipitation of its toluene solution, twice from methanol and twicefrom ethanol to give 1.1 g of white powder in 99.3% purity by HPLC. NMRspectra are in consistent with the structure expected. Both the startingbinaphthyl and the product are racemic mixtures of two possible isomersas evidenced by a double peak in HPLC profile and multiple bands in NMRspectra, especially in aliphatic region.

The concepts described herein will be further described in the followingexamples, which do not limit the scope of the invention described in theclaims.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and that one or more further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed.

In the foregoing specification, the concepts have been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that various modifications and changes can be madewithout departing from the scope of the invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope ofinvention.

Benefits, other advantages, and solutions to problems have beendescribed above with regard to specific embodiments. However, thebenefits, advantages, solutions to problems, and any feature(s) that maycause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeature of any or all the claims.

The use of numerical values in the various ranges specified herein isstated as approximations as though the minimum and maximum values withinthe stated ranges were both being preceded by the word “about.” In thismanner slight variations above and below the stated ranges can be usedto achieve substantially the same results as values within the ranges.Also, the disclosure of these ranges is intended as a continuous rangeincluding every value between the minimum and maximum average valuesincluding fractional values that can result when some of components ofone value are mixed with those of different value. Moreover, whenbroader and narrower ranges are disclosed, it is within thecontemplation of this invention to match a minimum value from one rangewith a maximum value from another range and vice versa.

It is to be appreciated that certain features are, for clarity,described herein in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures that are, for brevity, described in the context of a singleembodiment, may also be provided separately or in any subcombination.

1. A compound having the formula T-LG-T, where T is a charge transportmoiety having the formula —Ar¹-An-Ar² and LG is a linking group,wherein: An is a divalent anthracene moiety; Ar¹ is an aromatic groupselected from the group consisting of naphthyl, binaphthyl,naphthylphenylene, naphthylbiphenylene, and naphthylbinaphthylene; Ar²is an aromatic group selected from the group consisting of naphthyl,binaphthyl, naphthylphenylene, naphthylbiphenylene, andnaphthylbinaphthylene; and LG is a group having Formula I

wherein Q¹ and Q² are the same or different and are selected from thegroup consisting of alkyl, or Q¹ and Q² taken together are alkylene, andAr³ and Ar⁴ are the same or different and are selected from the groupconsisting of phenylene and naphthylene.
 2. An organic electronic devicecomprising a first electrical contact layer, a second electrical contactlayer, and a third layer therebetween, said third layer comprising acompound having the formula T-LG-T, where T is a charge transport moietyhaving the formula —Ar¹-An-Ar² and LG is a linking group, wherein: An isa divalent anthracene moiety; Ar¹ is an aromatic group selected from thegroup consisting of naphthyl, binaphthyl, naphthylphenylene,naphthylbiphenylene, and naphthylbinaphthylene; Ar² is an aromatic groupselected from the group consisting of naphthyl, binaphthyl,naphthylphenylene, naphthylbiphenylene, and naphthylbinaphthylene; andLG is a group having Formula I

wherein Q¹ and Q² are the same or different and are selected “from thegroup consisting of alkyl, or Q¹ and Q² taken together are alkylene, andAr³ and Ar⁴ are the same or different and are selected from the groupconsisting of phenylene and naphthylene.
 3. The device of claim 2,wherein said third layer further comprises an electroluminescentmaterial.
 4. A host material comprising a compound as in claims
 1. 5. Alayer comprising a host material comprising a compound as in claim
 1. 6.The layer of claim 5 further comprising an electroluminescent material.7. The compound of claim 1, wherein Q1 and Q2, are the same or differentand selected from methyl and trifluoromethy.
 8. The device of claim 2wherein Q¹ and Q², are the same or different and selected from methyland trifluoromethy.